What Is Lichen Planus?

Lichen planus is like a rash which is itchy and it is recurrent. It is characterized reddish purple flat topped bump having many sides. These bups can grow together to give the appearance of rough scaly patches. It may affect skin or mouth or both. It may also affect genital skin.
Lichen Planus is not an infectious disease. It is not a form of cancer it is not inherited and it is not related to nutrition. More commonly it is seen in the people who consume alcohol and do smoking. There is no specific treatment for lichen planus. It is a recurrent disease and takes long time to heal. Though it is not carcinogenic but if persists, it can become malignant by constant irritation of the lesion.

Cause of Lichen Planus

The cause is not known. It is mainly classified as autoimmune disease. Sometimes lichen planus is seen in the patients taking medication for high blood pressure, for arthritis or for some heart disease. Mostly it is seen as the allergic reaction to these medicines. It can be because of the chronic hepatitis C or because of the chronic graft and the host disease of the skin.

Incidence of Lichen Planus

• Occurs mostly in middle aged adults.
• Females are affected more commonly than males. (3:2)
• In lichen planus mucous membrane is frequently involved and is mostly asymptomatic.

Types of Lichen Planus

Lichen planus may be divided into following types:
By Configuration Annular Lichen Planus

• Linear Lichen Planus
• Morphology Of Lesion : Hypertrophic Lichen Planus
• Atrophic Lichen Planus
• Vesiculo bulbous Lichen Planus
• Ulcerative Lichen Planus
• Follicular Lichen Planus
•  Actinic Lichen Planus
• Lichen Planus Pigmentosus
   

By Site Of Involvement

• Lichen Planus Of Palms And Soles
• Mucosal Lichen Planus
• Lichen Planus Of Nails
• Lichen Planus Of Scalp
• Inverse Lichen Planus
• Special Forms : Drug Induced Lichen Planus
• Lupus Erythematosus- Lichen Planus Overlap Syndrome
• Lichen Planus Pemphigoides
• Keratosis Lichenoides Chronica
• Lichenoid Reaction Of Graft Versus Host Disease
• Lichenoid Keratosis
• Lichenoid Dermatitis

Symptoms of Lichen Planus

The symptoms of the lichen planus varies from site to site. Its intensity also varies .it can be mild, moderate or severe. Typical rash of lichen planus is described by “5P’s” that is it is well defined planar, pruritic, purple, polygonal papule. The onset f the Lichen planus may be sudden or it can show gradual appearance. Most commonly effected site is wrist and ankle.
When Lichen planus is there for the first time the attack may last for weeks or months and the recurrence can be there for years.

When the Lichen planus appears the lesion is initially 2 to 4 mm in diameter has angular borders and the color is violaceous. If the lesion persists hyperpigmentation may develop in the area.  The lesion is not there all the time. The cutaneous lesion amy wax and wane in between byrt reappears. If there is oral lesion that last for long than the cutaneous lesion.

What Does A Lichen Planus Look Like?

Lichen Planus Of Skin - It is characterized by reddish purple flat topped bumps that are few mm in diameters and may be itchy.

Lichen Planus On Wrist - May have a lacy appearance called Wickham’s Striae. May be present anywhere on body but favour the inside of wrists and ankles.

 
Lichen planus on legs is usually much darker. A variant of this disease is Hypertrophic Lichen Planus which is reddish brown and thick layer covered with scales. Occur specially on shins. This is especially itchy and persistent variant.  In Bulbous lichen planus blistera are present which s otherwise found very rarely.

Lichen planus of mouth - It is common. It occurs most commonly on the inside of cheeks but may affect tongue, lips and gums.

Lichen Planus Involving Buccal Mucosa

Lichen Planus Of Tongue

Lichen Planus Of Gums

Lichen Planus On Lips

More difficult to treat and last longer than lichen planus of skin. It looks like patches having fine dots and lines. It normally do not cause any problem. It is usually found during routine check up by dentists. Severe forms cause painful sores and ulcers in mouth. Sometimes Lichen planus of mouth is due to allergy to the dental materials but have been seen but are very rarely.
Oral rash occurs prior to any skin involvement. It is seen that oral lichen planus may be present in one of the 3 forms:
 

Reticular form is most common and manifests bilateral and asymptomatic lesion having small raised areas called as papules and the Wickham’s Striate.
Bullous form- Sometimes it is in bullous form which is fluid filled vesicles.
Erosive form- it shows red erythematous areas that are uncomfortable and ulcerated. In this erosion of the epetheliumcan be seen in many areas or in one area such as gums where it may resemble desquamative gingivitis. Wickham’s striate may be seen around the erosive areas and this has the malignant potential. Lichen planus can also affect the genital mucosa.
It is very rare that the Lichen planus of Esophagus is seen. If it is present it is erosive causing esophagitis. It is hypothesized that it is a precursor of squalors cell carcinoma of esophagus.

Microscopic Appearance of Lichen Planus Is Pathognomic, Hyperkeratosis with thickening of granular cell layer. There is development of “Saw tooth” appearance of rate pegs. It shows basal celldegeneration.  Inflammatory cells infiltrate into sub epithelial layer of connective tissue.

Diagnosis

usually it is very easy to diagnose Lichen Planus because of its peculiar form and characteristics.
If necessary, biopsy is the confirmatory test as it has very distinctive appearance under the microscope. Sometimes it is difficult to differentiate from other white lesions like leukoplakia but biopsy is helpful in such cases.

Differential Diagnosis

Oral lesions which resemble lichen planus are
Lichenoid reactions
Leukoplakia
Candidiasis
Pemphigus
Cicatricial pemphigoid
Erythema multiforme
Syphilis
Recurrent aphthae
Lupus erythematosus

Duration Of The Disease
Lichen planus goes away some times within 2 years but after healing it leaves dark brown mark on the skin which fades away with time. Oral lesions usually last longer than skin lesions.
In case of Lichen Planus like allergic reactions due to dental materials, patch testing may be done to pinpoint the allergy and it is recommended to remove the dental material.

Treatment of Lichen planus

As such there is no specific treatment for lichen planus but medication can be used to counter the symptoms of inflammation. After treatment it becomes dormant and can recur. One should try to find out the cause if alcohol or smoking is there it should be discontinued so that the chances of recurrence are less. Certain medicines which can be used to treat the Lichen planus are-

• Oral and topical Steroids
• Oral Retinoids
• Immunosuppressant medications
• Hydroxychloroquine
• Tacrolimus
• Dapsone
• Aloe vera
• UABNarrow Band Phototherapy
• Purslane

Prognosis

Lichen planus heals itself as there is no specific treatment for it. It takes around 4 years for the lichen planus to go but chances of recurrence are always there. It is better to find out the cause and remove it. If alcohol or the smoking is the cause then stop it. Clinical experience suggests that Lichen Planus of skin alone is easier to treat than if it is affecting the oral mucosa or there is genital lesion. 
It is seen that in patients with Oral Lichen Planus, there is a slight increase chances of oral cancer development. So it better not to consume alcohol and do smoking. Dermatologist should be consulted and it is recommended for oral cancer screening.
The incidence of malignant transformation is high in Erosive and Atrophic forms.

Lichen Planus In Children:

Oral Lichen Planus is rare in childhood.
In children it occurs preferentially in those of Asian race.
Clinical features resemble those of Oral Lichen Planus in adults.
Generally, the prognosis of Oral Lichen Planus seems to be more favorable in children than adults.